Steering catheters are catheters which are capable of passing through the arteriovenous system of a patient, typically to bring the distal tip of the catheter to a site of a stenotic lesion which threatens to occlude an artery, or to the heart itself for diagnosis, treatment, and the like. The catheter is "steerable" by rotation, typically having a curved tip, so that the catheter can be advanced along a desired pathway through the network of blood vessels. Such steerable catheters may carry a central steering wire which is attached to the catheter at both the proximal and distal ends, to provide to the catheter a torsional stiffness so that when the proximal end is rotated, the distal end of the catheter is correspondingly rotated. Additionally or alternatively, the catheter may carry a braided sheath within its tubular wall to provide added rotational stiffness as well as "pushability", which is a measure of longitudinal stiffness, without causing the catheter to be unduly laterally stiff so it cannot advance through the blood vessel system to its desired location.
Typically, in the prior art the surgeon who is performing a medical procedure with a steerable catheter advances the catheter while rotating a portion of the catheter outside of the body with his thumb and forefinger, all the while observing the progress of the catheter through a fluoroscope. This can be a difficult and inconvenient procedure because the catheter is typically very small in diameter so as to permit its entrance into smaller arteries and blood vessels. Thus, the catheter is hard to grip with the thumb and forefinger, and is also hard to rotate.
By this invention, a handle is provided to the catheter which is much more easily gripped by the surgeon, being typically of larger diameter than the catheter, and having a stationary portion for holding in the hand, plus a rotatable portion for rotational steering of the catheter. Also by this invention, the rotary handle is typically limited in the amount of rotation that it can perform, to consequently limit the overall rotation of the catheter to a given number of turns. This is advantageous in that it prevent excessive torque from being delivered to the catheter.
Additionally, it is possible to connect the catheter through the rotary handle of this invention to a source of fluid pressure for inflation of the catheter balloon when such a balloon is present, while at the same time rotating the catheter as desired by means of the rotary handle. The rotary handle may be held and manipulated with only one hand, but with substantially greater ease than a surgeon holds and manipulates the catheter per se. Furthermore, the handle of this invention may be connected to a catheter simply by inserting the proximal end of the catheter into the handle, with the handle providing sufficient gripping force to hold the catheter in use.